Neonatology Flashcards
Where is surfactant produced and what is its purpose?
Fluid produced by type II pneumocytes, reduces surface tension.
Not produced until 24-34 weeks gestation.
Keeps alveoli inflated, maximises surface area so increases compliance, reducing force needed to expand alveoli.
What are the cardio-respiratory changes at birth?
Adrenaline and cortisol released in response to birth, stimulating respiratory effort.
During first breaths - alveoli expand decreasing pulmonary vascular resistance.
This causes a fall in pressure in right atrium so left atrial pressure now greater and foramen ovale closes.
Increased blood oxygenation leads to drop in PGs so ductus arterioles shuts. Ductus venosus shuts because umbilical cord has been clamped.
What can occur in extended hypoxia?
Hypoxia occurs as contraction place placenta under stress, unable to carry out normal gas exchange.
Leads to anaerobic respiration, and fatal bradycardia.
Reduced consciousness, drop in respiratory effort.
Hypoxic ischaemic encephalopathy, could lead to cerebral palsy.
What are other key issues in neonatal resus?
Large surface area to weight ratio, so cold easily.
Born wet, so loose heat rapidly.
Born through meconium
What are the principles of neonatal resuscitation?
Warm baby; vigorous drying, heat lamp, plastic bag
APGAR score
Stimulate breathing
Inflation breaths - two cycles of five breaths
Chest compression if HR remains under 60 - 3:1
IV drugs and intubation
Possible HIE - active cooling
What is the APGAR score?
Appearance:
0 blue/pale, 1 bit blue, 2 pink
Pulse:
0 absent, 1 <100, 2 >100
Grimmace:
0 none, 1 little, 2 good
Activity:
0 floppy, 1 flexed, 2 active
Respiration:
0 absent, 1 slow/irregular, 2 strong/crying
What is the purpose of delayed cord clamping?
Provides time for fetal blood still in the placenta to reach the circulation of the baby - placental transfusion.
Leads to improved Hb stores, iron stores, BP and reduction in intraventricular haemorrhage and NEC.
Only negative effect is increase risk of neonatal jaundice.
If requires resuscitation, priority will be with resuscitations than cord clamping.
What care is provided immediately after birth?
Skin to skin Cord clamping Keeping baby dry and warm Vitamin K Label baby Measure weight and length
What is the purpose of Vit K injections?
Babies have a deficiency of Vit K when born.
IM injection given into thigh, key in clotting, prevents bleeding; intracranial, umbilical stump, GI bleeding.
What is the Guthrie test?
Blood spot screen heel prick
Screening card needs 4 separate drops, screens for 9 congenital conditions
Taken on day 5 (birth is 0)
Sickle cell Cystic fibrosis Congenital hypothyroidism Phenylketonuria Medium chain acyl CoA dehydrogenase deficiency Maple syrup urine disease Isovaleric acidaemia Glutaric aciduria type 1 Homocystin
Takes 6-8 weeks to come back
When is the NIPE completed?
Within first 72 hours after birth, and then repeated at 6-8 weeks by GP.
What are some important questions to ask before NIPE?
Has baby passed meconium
Baby feeding ok
FH of any congenital eye, heart or hip problems?
Pregnancy details, birth, breech presentation, abnormalities on antenatal scans
How are pre ductal and post ductal saturations measured?
Before the ductus arterioles closes within 1-3 days of birth.
Pre-ductal before the duct taken from right hand - receives blood from right subclavian from brachiocephalic in aorta before ductus arteriosus, and post ductal in either foot from descending aorta
What are we looking for on general appearance in the NIPE?
Colour - pink is good
Tone
Cry
What are we looking for in the head in the NIPE?
General appearance - size, shape, caput succedaneum, cephalohaematoma, injury
Circumference - occipital frontal circumference OCP
Anterior and posterior fontanelles, overlapping sutures common
Ears - skin tags, low set, asymmetry
Eyes - slight squints normal, epicanthic folds ?Down’s, purulent discharge
Check red reflex
Absent with congenital cataracts and retinoblastoma
Mouth - cleft lip, tongue tie, check suckling reflex, check palate
What are we looking for in the shoulders and arms in the NIPE?
Asymmetry - clavicle fracture
Movements - Erb’s palsy
Brachial and radial pulses
Palmar creases - single crease ?Down’s
Digits - number, straight or curved - clinodactyly
Sats probe on right wrist for pre ductal reading
What are we looking for in the chest in the NIPE?
Oxygen saturations Observe breathing Stridor, work of breathing Heart sounds, murmurs, rate Breath sounds, air entry
Auscultate lungs, heart
What are we looking for in the abdomen in the NIPE?
Observe shape
Concave - diaphragmatic hernia with abdominal contents in the chest
Umbilical stump - look for discharge, infection, hernia
Palpate for organomegaly, hernias, masses
Inspect and palpate
What are we looking for in the genitals in the NIPE?
Observe for sex, ambiguity, abnormalities
Palpate testes and scrotum, check present, descended, hernias or hydroceles
Inspect penis for hypospadias, epispadias, urination
Inspect anus to check patent
Ask about meconium
Inspect labia check not fused
Inspect clitorus, check for any vaginal discharge
What are we looking for in the legs in the NIPE?
Observe legs and hips for equal movements, skin creases, tone, talipes
Barlow’s and Ortolanis
Count the toes
What are we looking for in the back in the NIPE?
Inspect and palpate spine
Look for curvature
Spina bifida
Pilonidal sinus
What reflexes are tested in the NIPE?
Moro - when rapidly tipped back, arms and legs extend
Suckling - finger in mouth
Rooting - tickle cheek, turns towards the stimulus
Grasp - place finger in palm
Stepping - held upright, feet touch surface to make stepping motion
What are some common skin findings in the NIPE?
Haemangiomas Port wine stains Mongolian blue spot Cradle cap Desquamation Erythema toxic Milia - tiny white cysts Acne Naevus simplex - stork bite Moles Transient pustular melanosis
What is caput succedaneum?
Diffuse subcutaneous fluid collection, crosses suture lines
Caused by pressure on presenting part of head during delivery, resolves in first few days
What is a cephalhaematoma?
Subperiosteal haemorrhage
Bound by the periosteum so does not cross sutures
More common in instrumental delivery
May cause jaundice; monitor bilirubin
What is a subgaleal haemorrhage?
Occurs between aponeurosis of scalp and periosteum
Forms large fluctuant collection which crosses suture lines
Rare but life threatening blood loss
What is craniosynostonosis?
One or more of fibrous sutures prematurely fuses
Changes growth pattern of skull
Can result in raised intracranial pressure and damage to intracranial structures
Surgical intervention needed
What might a tense or sunken fontanelle indicate?
Tense bulging - raised ICP e.g. hydrocephalus
Sunken - dehydration
What is a cystic hygroma?
Congenital lymphatic lesion
Typically in left posterior triangle of the neck
Are benign but need surgery
What is caput succedaneum?
Fluid collects on the scalp, outside the periosteum
Caused by pressure to particular area of scalp - during traumatic, prolonged or instrumental delivery.
Crosses suture lines
Resolves in few days
What is a cephalohaematoma?
Collection of blood between skull and periosteum due to traumatic delivery
Does not cross suture lines
Risk of anaemia and jaundice
What is Erb’s palsy?
Injury to C5/C6 in brachial plexus
Associated with shoulder dystocia, traumatic or instrumental delivery, large birth weight.
Leads to weakness of shoulder abduction, external rotation, arm flexion, finger extension - waiters tip.
Function normally returns spontaneously within a few months.
Why might a fractured clavicle occur during birth and how does it present?
Shoulder dystocia, traumatic or instrumental delivery, large birth weight.
Noticable lack of arm movement
Asymmetry of movement in affected arm
Asymmetry of shoulders with affected shoulder lower than the normal shoulder
Pain and distress on movement of the arm
Conservative tx - immobilisation of the affected arm.
What common organisms can cause neonatal sepsis?
Group B strep - does not cause any problems for mother, but transferred in vagina - prophylactic antibiotics during labour
E Coli
Listeria
Klebsiella
Staph aureus
What are the risk factors for neonatal sepsis?
Vaginal GBS colonisation GBS in previous baby Maternal sepsis Chorioamnionitis Fever >38 Prematurity - less than 37 wks Early PROM Prolonged rupture of membranes
What are the clinical features of neonatal sepsis?
Non-specific Fever Reduced tone and activity Poor feeding Respiratory distress or apnoea Vomiting Tachycardia/bradycardia Hypoxia Jaundice within 24 hours Seizures Hypoglycaemia
What are the red flags for neonatal sepsis?
Confirmed or suspected sepsis in the mother
Signs of shock
Seizures
Term baby needing mechanical ventilation
Resp distress >4 hrs from birth
Presumed sepsis in another baby in a multiple pregnancy
What is the management of neonatal sepsis?
One risk factor or clinical features - monitor for 12 hrs
If two - start antibiotics
If red flag - start antibiotics
Start abx within 1 hr of decision
Blood cultures taken before abx, with baseline FBC, CRP
Perform LP if infection strongly suspected or features of meningitis
Benzylpenicillin or gentamicin
Check CRP at 24 hours
Blood cultures at 36 hours
If negative, consider stopping abx, check CRP at 5 days if still on treatment
Then consider stopping abx if clinically well, LP and BCs are negative at 5 days
What is it important to ask in a history to investigate neonatal sepsis?
Pregnancy:
Any concerns with growth, maternal illness, previous invasive infection
Labour and delivery:
duration of membrane rupture, fever during labour, GBS prophylaxis
Birth:
gestational age, weight, APGAR scores, any abnormalities on the NIPE
Since birth any feeding problems, passed urine and meconium, any interventions, any features of sepsis
What neurological features are indicative of neonatal sepsis?
Irritability, seizures, bulging fontanelle
Consider meningitis
What are some of the differentials of neonatal sepsis?
Congenital infections: TORCH Toxoplasmosis Other - syphilis, varicella, HIV Rubella Cytomegalovirus Herpes simplex virus
Respiratory distress syndrome Transient tachypnoea of the newborn Necrotising enterocolitis Congenital pneumonia Congenital heart disease HDN Metabolic diseases - galactosaemia
What specific antibiotics are required for specific symptoms in neonatal sepsis?
Flucloxacillin if late onset
Amoxicillin and cefotaxime IV if meningitis suspected
Metronidazole for NEC
Antifungal e.g. amphotericin B for fungal sepsis
Add aciclovir if HSV suspected
What are some of the complications of neonatal sepsis?
Poor cognitive development Visual or hearing deficits Cerebral palsy Bronchopulmonary dysplasia Death
What is the physiology behind jaundice?
RBCs broken down into bilirubin - unconjugated circulates bound to albumin, and some is free - can cross blood brain barrier.
UGT converts unconjugated to conjugated - cannot cross blood brain barrier, metabolised and excreted in urine and faeces.
What is the process of normal physiological jaundice?
Unconjugated bilirubin, presents on second or third day of life.
Due to shorter lifespan of neonatal RBCs, immature liver at birth, high concentration of beta glucuronidase which converts conjugated back to unconjugated.
Why are some neonates more prone to jaundice?
Preterm babies - higher bilirubin levels.
Breastfed babies - experience more marked and prolonged jaundice
Babies with significant bruising or cephalohaematoma - can occur following difficult deliveries
